Catalytic molecular association of aldehydes



Patented June 28, 1932 UNITED STATES. PATENT: OFFICE ALPHONSO. J' AEGER, OF GRAFTON, PENNSYLVANIA, ASSIGNOR TO THE SELDEN COM- PANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF DELAWARE I CATALYTIC MOLECULAR ASSOCIATION OF ALDEHYDES No Drawing. I Original application filed March 23, 1928, Serial No. 264,275. Divided and this application filed March 28, 1929.

This invention relates to polymerization and condensation of aldehydes.

According to the present invention polymerization and condensation of aldehydes. V 5 According to the present invention polymerization and condensation productsof al hydes, such as aldolizations, condensation etc..are carried out particularly in the vapor phase by means of a new class of contact masses. The contact masses used in the pres ent invention contain base exchange bodies or their derivatives. Under-the term base exchange body are included all natural or artificial bodies which possess the properties of exchanging their basesfor other bases of salt solutions. The base exchanging products used in making catalytic compositions of the present invention or as initial material for derivatives to be so used may possess high base exchanging power or in many cases may possess lower base exchanging power, since the catalytic value of the final compositions is not primarily dependent on the amount of base exchanging power present. In general the base exchange bodies may be divided into two main catgoriesz-Two component and multi-component zeolites, i. e., base exchangebodies containing chemically combined silicon in their nucleus and non-silicious base exchange bodies in which all of thesilicon is replaced by other suitableacidic or amphq; -theric metal oxides. Two+component zeolites are the reaction products of two types of initial components, that is to say, metallates and silicates, (usingthe' term-metallate in a somewhat broader sense as will be defined further on in the description), or metal salts andsilicates. Frequently more than one member of a type may enter into reaction, that is to say, a silicatediiay react with more than one metallate or more than one metal salt. The multi-component zeolites are the reaction products of at least three types of components, that is to.say, at least one-silicate, at least one metallate, and at least one metal salt.

The base exchange bodies, both zeolites and non-silicious base exchange bodies, may be associated with diluents prei'brably in the Q form of a physically homogeneous structure,

Serial No. 350,829.

as will be described below. Either diluted or undiluted base exchange bodies may be present inthe contact masses used in the present invention, or their derivatives may be present, but it should be understood that .wherever base exchange bodies are referred to both diluted and undiluted products are included.

Base exchange bodies, both zeolites and non-silicious base exchange bodies, may also be transformed into derivatives which possess many of the chemical and most of the physical characteristics of the parent base exchange bodies. Such derivatives may be salt-like bodies, that is to say, the reaction products of base exchange bodies with compounds containing anions capable of'reacting with the base exchange bodies to form products which possess many of the properties of salts. A further class of derivatives are the acid'leached base exchangebodies. When a base exchange body is subjected to leaching by acids, particularly dilute mineral acids, the exchangeable bases are first gradually removed. The resulting products contain both the more basic and the more acidic components of the non-exchangeable nucleus of the base exchange body, w1th or without a portion of the exchangeable bases. As the leaching is carried on further, more and more of the relatively positive components of the non-exchangeable nucleus are re-' moved, and if carried to completion the leached product contains only the relatively acid components of the non-exchangeable nuuct from long continued leaching is a com plex silicic acid'which has many of the physical properties of the original base exchange 85. cleus. In the case of zeolites the final prod-- leaching of these base exchange bodies and the salt-like bodies obtained by the reaction of these base exchange bodies with compounds the acid radicals of which are capable of reacting with the base exchange bodies to produce products which show most of the properties of salts. When used in the claims,

the term permutogenetic will have no.0ther meaning.

Catalytically active components may be associated with diluted or undiluted permutogenetic bodies in four main forms, as follows :-(1) They may be physically admixed with or impregnated into the permutogenetic products. (2) They may be physically homogeneously incorporated into the permutogenetic products before the latter have been completely formed in the form of catalytically active diluent bodies or in the form of diluents which have been impregnated with catalytically active substances. (3) They may be chemically combined with or in the permutogenetic products in non-exchange able form, that is to say, they may form a part of the non-exchangeable nucleus of the base exchange body present in the final contact mass or which is transformed into the 'derivatives,,or they may be chemically combined with the base exchange bodies in the form of catalytically active anions which form with the base exchange body salt-like bodies. (4) They may be chemically combined in exchangeable form either during the formation of the base exchange body or by base exchange after formation. Obviously of course the same or-difierent catalytically active components may be present in mbre than one of the above described forms, and it is an advantage of the present invention that catalytically active substances may be. introduced in a wide variety of forms which gives a large field of choice to the catalytic chemist.

While the different permutogenetic products may vary widely in their chemical characteristics, they all possess a similar physical structure which is characterized by more or less high porosity, frequently microporosity, and great resistance to high temperature, and in the case of products which have not been acid leached to the point of removal of catalytically active components these compo-- nents are distributed throughout the framework of the products in atomic or molecular dispersion, as will be described in greater detail below, and this chemical homogeneity is one of the important advantages of some of the contact masses ofthe present invention.

V While three of the methods of combination of the catalytically active substances may be effected with undiluted as well as diluigd permutogenetic products, it has'be'en found that for most reactions homogeneously diluted permutogenetic contact masses are of ad vantage, particularly where the diluents are of a physical nature such as to exert a desired influence on a catalytic activity of the contact masses, as when, for example, diluents are rich in silica, which has been found to "have an activating power, orwhere the diluents by reasonof high porosity,capi1larity,

or surface energy may be considered as physical catalysts oract-ivators.

Base exchange bodies used in contact masses of the present invention behave as if they were products of extremely high molecular weight for catalytically active components can be introduced either into the nonexchan'geable nucleus or in the form of .exchangeable bases in practically any desirable proportions and the ordinary law of chemical combining proportions, which in compounds of low molecular weight restricts the proper tions in which components can be incorporated chemically, appears to be without force, which makes it reasonable to assume that the molecular weight is so high as to completely mask the effect of the law. It is of course possible that the base exchange bodies, or

some of them, may be solid solutions of a plurality of related compounds of lower molecular weight. It has not been'possible hitherto to definitely settle this question, as base exchange bodies are not readily capable of structural chemical analysis. The present invention is of course not limited to any theory, but irespective of the underlying reasons the fact that catalytically active components may be chemically introduced in any desired proportions is of enormous importance to the catalytic chemist and gives him the power to produce an almost unlimited number of finely and gradually toned catalysts or contact masses for the molecular association of organic compounds and in all cases the contact masses produced are highly effective by reason of the desirable physical structure of the permuto'genetic products contained therein and the wide limits of homogepresent invention are peculiarly adapted.

In addition to the important characteristics with which permutogenetic products endow the contact masses of the present invention it has been found that for many of the reactions coming within the scope of the present invention, it is desirable to stabilize the contact masses, and this may be effected by associating with the permutogenetic products or incorporating or forming therein compounds of the alkali forming metals, that is to say, the alkali metals, the alkaline earth metals, and the strongly basic earth metals. These compounds appear to slow up or smooth out the catalytic reaction, and will be referred to throughout this specification as stabilizers. The stabilizers may be nonalkaline, weakly alkaline or strongly alkaline, depending on the reaction products and on the nature of the catalytically active compresent invention that intie normal formaponents used. It is great advantage of the the splitting off of water.

ent invention it has been found that the stabilizer action and the overall efiiciency of the contact masses can in many cases be greatly increased or enhanced by the association therewith or chemical combination therein of elements or radicals or groups which are catalytically active but do not possess specific catalytic activity for the particular reaction to be carried out. Many reactions involve In such reactions it is very desirable to incorporate catalysts or catalytic components which are not specific association catalysts but which may favor dehydration, or splitting off of carbon dioxide. Such catalysts or catalytic components .which are not specific catalysts for the reaction iriwhich they are being used under the reaction conditions obtaining will be referred to throughout the specification as stabilizer promoters, as they appear to enhance the ftoning effect which can be achieved by stabilizers. The use of this expression should, however, in no sense be taken-to limit the invention toa particular theory of action of these non-specific catalysts and in fact in some cases stabilizer promoters may be present where there are no stabilizers.

The tremendous range of chemical groups which may be combined in or with or incorporated in permutogenetic products permits a wide choice of stabilizer promoters as well as specific catalysts and permits their association with the contact masses in an extremely homogeneous and catalytically eflicient form.

' Thus many base exchange bodies or their derivatives. may be considered as complex catalysts, stabilizers and stabilizer promoters, as.

all of these elements may be present in the same chemical com ound-- and sharing the advantages flowing From its desirable physical. structure and chemical properties. Of course both stabilizer and stabilizer promoters may be mixed partly or wholly with permutogenetic products and a singlestabilizer or single stabilizer promoter may be present partly in physical admixture and partly in chemical combination, as will be clear to the skilled base exchange chemist.

' The base exchange bodies which form the important components or-initial "material for derivatives in contact masses of the present high base exchanging invention may be prepared by any of the well known methods. Thus for example, twocomponent zeolites may be prepared by wet methods, in which the metallate components or metal salt components, part or all of which may be catalytically active, are caused to react with soluble silicates to form zeolites of alumino silicate or aluminum double silicate types, or the components may be fused, preferably in the presence of fluxes. It should be understood that under'the term metallate is included not only the alkaline solutions of amphoteric metal oxides or hydroxides but also alkali forming metal salts of metal acids, such as the oxyacids of metals of the fifth and sixth groups, which in at least'one stage of oxidation are not strictly speaking ampho-' -teric, but which products are capable of reacting with silicates to form zeolites, or with other components to form non-silicious base exchangebodies. Throughout the specification this somewhat more general definition of metallates will be strictly adhered to. In

the formation of two-component zeolites by such circumstances are homogeneous chemicalcompounds, although in many ways they behave as such. There is, however, reason to believe thatin some cases at least mixtures'of base exchanging and non-base ex- -changing polysilicates may be produced.

For the purpose of the present specification a product will be considered as a base exchange product if it has any base exchange. power at all. Y

It is desirable for many purposes and particularly where "two-component zeolites of power are needed to .add the relatively acid component, for example, metal salts in the case of aluminum double silicate type of silicates, to the relatively more alkaline components such as for example soluble silicates. By these means a continuous alkalinity is insured, and this method may be considered as the preferred method in most cases, but the opposite procedure is advantageous for certain contact masses and inc'ludedjn the invention.

Multi-component zeolites may be prepared bv any of the foregoing methods using at least three types of components, that is to say, at least one metallate, at least one metal salt and at least one soluble silicate. In the ponent zeolites produced vary in their nature,

proportion of the different dependent on the Thus where the metalreacting components.

lates and silicates predominate over the metal salts the resulting products resemble the alumino silicate type of two-component zeolites. If the metal salts and silicates predominate over the metallates the products resemble the aluminum double silicate type of twocomponent zeolites, and finally if the metallates and metal salts predominate over the silicates the resulting product resembles more or less non-silicious base exchange bodies. It

will be clear that there is no sharp defining line between the three types of multi-com ponent zeolites, and one shades into the other as the proportions of the different components vary. It is an advantage of the multicomponent zeolites over the two-component zeolites that the choice of catalytically active components is wider, as some catalytically active elements or groups can only be incor porated in the form of metallates and others only in the form of metal salts. In a multicomponent zeolite each catalytically active group can be incorporated in the form in which it is best available.

Non-silicious base exchange bodies are produced by the general methods described above, but instead of bringing about reactions between silicates and other metal oxide components, two or more oxymetal compounds are caused to react, in general, at least one will be a metallate and at least one a metal salt, or in some cases it is possible to bring about action between two different metallates in which one negative radical is more acidic than the other. It is possible to produce nonsilicious base exchange bodies in which a single metal is present. .Thus for example, some metals may be suificiently amphoteric in character to form both inetallates and metal salts which are capable of reacting with each other to produce base exchange bodies.

A special method of producing non-silicious base exchange bodies consists in the gradual neutralization of strongly alkaline salts of the oxyacids of metal elements of the fifth and sixth groups in stages of oxidation in which they are sufliciently amphoteric. The neutralization of other strongly alkaline metallates-may' also bring about formationpzef non-silicious base exchange bodies. The converse method, whereby non-alkaline salts of suitable metals are gradually treated with alkali until the reaction is sufficiently alkaline to permit the formation of base exchange bodies, may also be used.

Many metals are capable of entering into the base exchange formation only in certain stages of oxidation, and it is cometimes necessary to introduce such metals in a stage of oxidation different from that desired in the final base exchange body, the change of stage of oxidation being preferably eflected during the formation of the base exchange body. Certain other elements may be incorporated in the form of complex compounds of the most various types, such as for example, ammonia complexes and the like.

In addition to the artificial base exchange bodies briefly described above, neutral base exchange bodies, such as nepheline, leucite, felspar, and the like, may be used.

The most important contact masses for many reactions contain permutogenetic products,'in which preferably the diluents are homogeneously incorporated into the base exchange bodies before formation of the latter, or at least before the base exchan e body has set" after formation. -Many diluents, both inert, stabilizing, activating, catalytically active, or having stabilizer promoter effects, can be used. A few of the diluents will be briefly enumerated :kieselguhrs of all kinds, particularly natural or treated celite earth, silicious powders of various types, powdered permutogenetic products, natural or artificial powders of rocks, stones, tufis,

lers earth, talc, glass powder, pumice meal,

asbestos, graphite, activated carbon, quartz meal, .various pulverized minerals rich 1n quartz, metal powders and metal alloy powders, salts of oxymetal acids such as tungstates, vanadates, chromates, uranates, manganates, cerates, molybdates. etc., particularly copper salts of the above, silicates, such as copper silicate, iron silicate, nickel silicate, cobalt silicate, aluminum silicate, titanium silicate, minerals or ores, especially those rich in copper, etc. Finely divided diluents are of great advantage, especially when the average particle size is less than 60 microns, in which case the diluents possess high surface energy, which increases the adsorptive and absorptive capacity of the contact mass, the diffusion speed and porosity. These finely divideddiluents may be considered as physical catalysts or activators. Di;

luted permutogenetic bodies may also be or more liquid components of the base ex-,

. active gases.

change bodies to be formed when the latter are prepared by wet methods.

(2) Components, either catalytically active, stabilizer promoters, or others, may be precipitated or impregnated into diluent bodies which are then incorporated into the (4) Diluents may he formed during the formation of base exchange bodies by mixing suitable compounds with the components of the base exchange bodies so that the diluent particles are precipitated during formation. Protective colloids may be added to prevent coagulation of the diluent particles before the base exchange bodies have become sufiiciently set.

(5) Compounds may be added which react with certain of the base exchange bodies forming components to produce diluents, for instance salts of the metal acids of the fifth and sixth groups maybe added in suflicient excess so that they react with components of the base exchange body to form insoluble diluents, as for example the heavy metal oxides.

(6) Preformed base exchange bodies, diluted or undiluted, artificial or natural, can be impregnated with true or colloidal solutions of catalytically eflfective components and then dried.

(7) A preformed base exchange body, diluted or undiluted, may be impregnated with a plurality of solutions which react therein to precipitate any desired diluents.

(8) Soluble diluent compounds may be added to the components forming'a base exchange body, which after formation retains the compounds in solution and is dried with- "change bodies may be substituted by base exout washing or is treated to precipitate the compounds.

(9) Natural base exchange bodies or artificial base exchange bodies, diluted orundiluted, or their derivatives, may be impregnated with solutions of the desired compounds, which are then precipitated by means of re- The nucleus or non-exchangeable portion of the molecules ofthe base exchange bodies is ordinarily considered to consist of two types of oxidesmamely, relatively basic metal oxides, usually amphoteric, and relatively acidic oxides, such as SiO some ainphoteric metal oxides and some metal oxides which have a distinctly acid character. The nusplit by ordinary chemical means, but it is advantageous to consider the two portions of the nucleus as the basic and'acidic portions, hearing in mind of course that the nucleus behaves as a single group. The metal compounds which are capable of forming the asic portion of the nucleus are those of the following metals -copper, silver, gold, bismuth, beryllium, zinc, cadmium, boron, aluminum, some rare earths, titanium, zirconium, tin, lead, thorium, niobium, antimony,

tantalum, chromium, molybdenum, tungsten,

uranium, vanadium, manganese, iron, nickel, cobalt, platinum, palladium. Compounds of these elements may be introduced singly or in mixtures, in any desired proportions, and may be in the form of simple or complex ions.

It should be understood that some of the ele-,.

ments in certain stages of oxidation may be introduced either as metallates or metal salts. Others may beintroduced in only one form, and still others may be introduced in a stage of oxidation other than that desired in the final base exchange body or in the form of complex compounds. Among the complex ionogens are ammonia, hydroxyanic acid, oxalic acid, formic acid, tartaric acid, citric acid, glycerine, and the like.

Many of the metals are specific catalysts, others are stabilizers, and still others are stahilizer promoters. Naturally the status ofan element as catalyst or stabilizer promoter will vary with the particular reaction for which the final contact mass is to be used, and the choice of catalysts and stabilizer promoters together with the proportions will be determined by the particular molecular asso-' ciation of organiccompoundsfor which the contact mass is to be used.

Examples of components forming the'relatively acid portion of the base exchangenucleus are alkali metal silicates, which are soluble in alkali, and alkali metal salts of acids, such as those ofboron, phosphorus, nitrogen, tin, titanium, vanadium, tungsten, chromium, niobium, tantalum, uranium, an-

timony, manganese, etc.

The exchangeable bases of the base exgold, ammonium, beryllium, calcium, man-- vganese, caesium, potassium, sodium, zinc, strontlum, cadmium, barlum, lead, aluminum, scandium, titanium, zirconium, tin, an-

timony, thorium, vanadium, lithium, rubidium, thallium, bismuth, chro'mium, uraniu1'n, manganese, iron, cobalt, nickel, ruthenium, palladium, platinum and cerium.

Depending on the reactionsin which the contact mass is to be'used, theexchangeable bases introduced may be specific catalysts, they may be stabilizers, or they may be stabicleus behaves as a single anion and cannot be lizer promoters. They may be introduced as tact mass, improve its physical strength, or

both.

"5 As has beeri described above, base exchange bodies can be caused to react with compounds containing acidic radicals capa ble of forming therewith salt-like bodies. The radicals may be present in the form of simple acid radicals, polyacid radicals: or complex acid radicals, and include radicals containing the following elements :chromium, vanadium, tungsten, uranium, molybdenum, manganese, tantalum, niobium, antimony, selenium, tellurium, phosphorus, bismuth, tin, chlorine, platinum, boron. Among the complex radicals are ferro and ferricyanogen, certain ammonia complexes and the like. The amount of acid radicals caused to unite with the base exchange bodies -to form salt-like bodies may be varied so that the resulting products may possess the character of acid, neutral or basic salts. Many of these acid radicals are stabilizers or stabilizer promoters for the catalytic molecular associations of organic compounds.

The base exchange bodies diluted or undiluted, or some of their salt-like body derivatives, may be treated with acids, such as mineral acids, for example, 210%,sulfuric, hydrochloric or nitric acids, to remove part or all of the exchangeable bases, or also part or all of the basic portion of the nucleus.

In the case of zeolites, the partial leaching with acids, which leaves part or ally of the basic portion of the nucleus or even part of the exchangeable bases, does not affect the function of the zeolites as catalysts when they contain catalytically active elements in the basic portion of the nucleus, or in some cases even exchangeable bases, and such partially leached catalysts vare of great importanoe inmany reactions. Where the leaching is carried out to completion the advantageous physical structure remains to a considerable extent the same but the remainder is of course a form of silica, or in the case of zeolites in whichpart of the silica is replaced by other acidic compounds, a mixture of the two,

I and usually will not be a specific catalyst for the reactions of the present invention. It serves, however, as an advantageous physical carrier of specific catalysts, and in the case of partially substituted zeolites may also contain stabilizer promoters.

Leached non-siliciou's' base exchange bodies, either partially or completely leached, may contain catalytically active components and behave as catalysts, stabilizer promoters or both, and many important catalysts are thus obtained. This is particularly the case for reactions where a relatively alkali-free contact mass is required for best results and wnere' the alkali content of a contact mass themselves catalysts.

,sponding zincate containing a base exchange body may be too great. for optimum results.

'or may be impregnated therein. The massive carriers may be inert, activating, or For example, certain catalytic metal alloys and minerals, fall within this class. -Aluminum or copper alloy granules perform an additional advantageous function in that their relatively high heat conductivity tends to prevent local overheating in exothermic reactlons, which is of considerable importance in obtaining good yields, as many of the reactions, are equilibri um reactions, and at higher temperatures the equilibrium may be adversely aflected. with resulting lowering of yields and contamina: tion of the product.

Ewample their derivatives,

Aldolizations and crotonizations may be (2) 30 parts of zinc nitrate, containing 6 mols of water, are dissolved in 100 parts of water, and also transformed into the correhydroxidei v (3) 5.5 arts of thorium nitrate, containing 12 1110 s of water, are dissolved in 100 parts of water.

- (4) 25 parts of zirconium nitrate, containing 5 mols of water, are dissolved in 200-250 parts of water.

Solutions 1 and 2 are poured together, and pulverized, unglazed porcelain is added until the suspension just remains readily stirrable.

Thereupon a mixture of solutions 3 and 4 is added, care beln taken thattlie reaction mixture remains al aline or neutral to phenolphthalein. The body obtained, which is a diluted base exchange body, is separated from the mother liquor in the usual manner, dried at temperatures preferably below 100 C., hydrated by trickling water over it, and again dried, after which it is ready for use.

The contact mass is placed in a converter in a thick layer and vapors of acetaldehyde are passed over it at 80200 C. and are transformed into aldol or crotonaldehyde, de

by means of 5 N. sodium pending on the reaction conditions. "The crotonaldehyde obtained can be used as. a raw materialfor the production of butyl alcohol by reddctio'n'with hydrogen in the presence of contact masses containing copper.

"A modified contact mass can be obtained by trickling a. 1 to 2% nitric acid solution over the base exchange body in order to leach out ise part or all of the exchangeable alkali. Other modified contact masses can be obtained by introducing cadmium or titanium by base exchange, or by forming the salt like bodies with the metal acids of the fifth or sixth group of the periodic system.

Base exchange bodies containin Si'O in the nucleus may be obtained by su stituting waterglass for part of the metallates. Such contact masses, especially when leached with acid, are very effective.

Instead of or in addition to using unglazed porcelain as a diluent other diluents, such as asbestos, kieselguhr, quartz, and the like, may be used.

This application is a division of my prior application Serial No. 264,275, filed March 23, 1928.

What is claimed as new is:

l. The method which comprises subjecting an aldehyde to the action of a condensation contact mass containing a permutogenetic body at temperatures of 200 C.

2. A. method of effecting vapor phase acetaldehyde associations, which comprises causing the vapors of an acetaldehyde to contact at temperatures of 80200 C. with a contact mass containing at least one permu togenetic body.

3. A method of effecting association of acetaldehyde, which comprises causing the vapors of acctaldehyde to pass at a temperature of 80200 C. over a contact mass containing at least one permutogenetic body.

4. A method according to claim 2, in which the permutogenetic body contains condensation catalytic elements chemically combined in or with the perinutogenetic body.

Signed at Pittsburgh, Pennsylvania, this 23rd day of March, 1929.

ALPHON S O. JAEGER. 

